Initial CI20 support

[Michael <macallan%netbsd.org@localhost>]

Hello,

I just committed initial support for the MIPS Creator CI20 board.
Not much to see yet, it loads a kernel, spits some info to the serial
console and you can poke around using ddb.
What works:
- CPU identification / setup as MIPS32r2
- basic timer support ( there's no cycle counter so we use the
  'Operating System Timer' at 12MHz )
- serial port
- reset

What doesn't work:
- interrupts. There's no support for the interrupt controller yet.
- everything else

Here's the obligatory boot log:

U-Boot SPL 2013.10-rc3-g9329ab16a204 (Jun 26 2014 - 09:43:22)
SDRAM H5TQ2G83CFR initialization... done


U-Boot 2013.10-rc3-g9329ab16a204 (Jun 26 2014 - 09:43:22)

Board: ci20 (Ingenic XBurst JZ4780 SoC)
DRAM:  1 GiB
NAND:  8192 MiB
MMC:   jz_mmc msc1: 0
In:    eserial3
Out:   eserial3
Err:   eserial3
Net:   dm9000
ci20# dhcp
ERROR: resetting DM9000 -> not responding
dm9000 i/o: 0xb6000000, id: 0x90000a46 
DM9000: running in 8 bit mode
MAC: d0:31:10:ff:7e:89
operating at 100M full duplex mode
BOOTP broadcast 1
DHCP client bound to address 192.168.0.47
*** Warning: no boot file name; using 'C0A8002F.img'
Using dm9000 device
TFTP from server 192.168.0.44; our IP address is 192.168.0.47
Filename 'C0A8002F.img'.
Load address: 0x88000000
Loading: #################################################################
	 ##############
	 284.2 KiB/s
done
Bytes transferred = 1146945 (118041 hex)
ci20# bootm
## Booting kernel from Legacy Image at 88000000 ...
   Image Name:   evbmips 7.99.1 (CI20)
   Image Type:   MIPS NetBSD Kernel Image (gzip compressed)
   Data Size:    1146881 Bytes = 1.1 MiB
   Load Address: 80020000
   Entry Point:  80020000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK
subcommand not supported
ci20# g 80020000
## Starting applicatpmap_steal_memory: seg 0: 0x30c 0x30c 0xffff 0xffff
Loaded initial symtab at 0x802502d4, strtab at 0x80270cb4, # entries 8323
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
    2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014
    The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 7.99.1 (CI20) #113: Sat Nov 22 09:58:39 EST 2014
	ml@blackbush:/home/build/obj_evbmips32/sys/arch/evbmips/compile/CI20
Ingenic XBurst
total memory = 1024 MB
avail memory = 1001 MB
kern.module.path=/stand/evbmips/7.99.1/modules
mainbus0 (root)
cpu0 at mainbus0: 1200.00MHz (hz cycles = 120000, delay divisor = 12)
cpu0: Ingenic XBurst (0x3ee1024f) Rev. 79 with unknown FPC type (0x330000) Rev. 0
cpu0: 32 TLB entries, 16MB max page size
cpu0: 32KB/32B 8-way set-associative L1 instruction cache
cpu0: 32KB/32B 8-way set-associative write-back L1 data cache
com0 at mainbus0: Ingenic UART, working fifo
com0: console

root device: 

Let me know if I broke anything.

have fun
Michael